Stromal cell derived factor-2 (Sdf2): a novel protein expressed in mouse

Area of Science:

• Cell Biology
• Molecular Biology
• Biochemistry

Background:

• The stromal derived factor (SDF) family includes molecules generated by stromal cells, with SDF1 and SDF4 identified as chemokines.
• SDF2 and SDF5 functions are not yet defined. Sdf2 has a paralogous gene, Sdf2l1, in humans and mice, with significant sequence similarity.
• SDF2L1 is an endoplasmic reticulum (ER)-stress inducible gene in humans, and a similar protein in Arabidopsis thaliana activates the unfolded protein response (UPR) under ER-stress.

Purpose of the Study:

• To clone, express, and purify recombinant mouse Sdf2.
• To generate an antibody against Sdf2 to investigate its expression and localization.
• To explore the potential role of mouse Sdf2 in ER-stress and the UPR by comparing its structure and sequence to known homologs.

Main Methods:

• Cloning and expression of recombinant Sdf2.
• Purification of recombinant Sdf2 and antibody generation.
• Tissue expression analysis, subcellular localization studies, protein sequence and 3D structure analysis, and multiple sequence alignment.

Main Results:

• Recombinant Sdf2 was successfully cloned, expressed, and purified, and an anti-Sdf2 antibody was raised.
• Sdf2 protein is expressed in multiple tissues and localized to the endoplasmic reticulum.
• Structural and sequence analysis suggests Sdf2 is ER-resident, potentially through accessory proteins, and shares conserved features with other Sdf2-like proteins involved in ER-stress.

Conclusions:

• Mouse Sdf2 is an ER-resident protein, despite lacking canonical ER-retention signals.
• The structural and sequence conservation suggests a role for mouse Sdf2 in the Unfolded Protein Response and ER-stress.
• Identifying novel factors like Sdf2 involved in ER-stress pathways is crucial for understanding diseases such as cancer and diabetes and for developing therapeutic targets.